CN117320796A - Method and apparatus for recovering carbon dioxide from combustion engine exhaust - Google Patents

Method and apparatus for recovering carbon dioxide from combustion engine exhaust Download PDF

Info

Publication number
CN117320796A
CN117320796A CN202180080203.4A CN202180080203A CN117320796A CN 117320796 A CN117320796 A CN 117320796A CN 202180080203 A CN202180080203 A CN 202180080203A CN 117320796 A CN117320796 A CN 117320796A
Authority
CN
China
Prior art keywords
stream
exhaust
combustion engine
fuel
liquefied
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202180080203.4A
Other languages
Chinese (zh)
Inventor
尼古拉·费尔巴布
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LGE IP Management Co Ltd
Original Assignee
LGE IP Management Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by LGE IP Management Co Ltd filed Critical LGE IP Management Co Ltd
Publication of CN117320796A publication Critical patent/CN117320796A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/26—Drying gases or vapours
    • B01D53/265—Drying gases or vapours by refrigeration (condensation)
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/06—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by partial condensation
    • F25J3/063—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by partial condensation characterised by the separated product stream
    • F25J3/067—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by partial condensation characterised by the separated product stream separation of carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/002—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by condensation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
    • B01D53/047—Pressure swing adsorption
    • B01D53/0476—Vacuum pressure swing adsorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/62—Carbon oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/08—Separating gaseous impurities from gases or gaseous mixtures or from liquefied gases or liquefied gaseous mixtures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/18—Noble gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/22—Carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/50—Carbon oxides
    • B01D2257/504—Carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/018—Natural gas engines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/025—Other waste gases from metallurgy plants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/04—Mixing or blending of fluids with the feed stream
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/50—Oxygen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/62—Liquefied natural gas [LNG]; Natural gas liquids [NGL]; Liquefied petroleum gas [LPG]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/70—Flue or combustion exhaust gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2215/00—Processes characterised by the type or other details of the product stream
    • F25J2215/04—Recovery of liquid products
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2220/00—Processes or apparatus involving steps for the removal of impurities
    • F25J2220/80—Separating impurities from carbon dioxide, e.g. H2O or water-soluble contaminants
    • F25J2220/82—Separating low boiling, i.e. more volatile components, e.g. He, H2, CO, Air gases, CH4
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/30—Compression of the feed stream
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2245/00—Processes or apparatus involving steps for recycling of process streams
    • F25J2245/02—Recycle of a stream in general, e.g. a by-pass stream
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2270/00—Refrigeration techniques used
    • F25J2270/02—Internal refrigeration with liquid vaporising loop
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2270/00—Refrigeration techniques used
    • F25J2270/90—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
    • F25J2270/904—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration by liquid or gaseous cryogen in an open loop
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/40—Capture or disposal of greenhouse gases of CO2

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Analytical Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Combustion & Propulsion (AREA)
  • Treating Waste Gases (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

A method and apparatus for recovering carbon dioxide (CO 2) from an oxy-fuel combustion engine exhaust stream is described. The method comprises the following steps: providing and separating an oxy-fuel combustion engine exhaust stream to provide a first liquefied CO2 stream and a first exhaust stream; condensing at least a portion of the first offgas stream to provide a partially condensed offgas stream; and separating the condensed waste gas stream to provide a second waste gas stream and a second liquefied CO2 stream.

Description

Method and apparatus for recovering carbon dioxide from combustion engine exhaust
The present invention relates to a method and apparatus for improving the recovery or capture of carbon dioxide from combustion engine exhaust, particularly oxyfuel internal combustion engine exhaust. Suitable fuels for oxyfuelled internal combustion engine exhaust gas include liquefied oxygen and liquefied hydrocarbon fuels (e.g., liquefied natural gas).
For standard combustion in conventional combustion engines, the oxidant used is air, which contains oxygen (21 mol%) and most of the nitrogen (78 mol%). Nitrogen (N2) is an inert gas that does not participate in the combustion reaction, but which can lower the combustion temperature. Due to the amount of N2 in the intake air, the exhaust gas typically contains mainly N2, with carbon dioxide (CO 2) and water as minor components. This dilution of the vented CO2 with N2 makes separation to generate a pure CO2 stream for capture and storage (to avoid emission to the atmosphere simply as a greenhouse gas) difficult.
Oxyfuel combustion is the process of combusting a fuel with 'pure' oxygen (rather than air as the primary oxidant). The exhaust gas thus produced mainly contains carbon dioxide and water. Water can be easily removed by ambient cooling, so carbon dioxide capture using carbon capture and storage (carbon capture and storage, CCS) technology should be easier. Typically, CCS involves liquefying gaseous carbon dioxide in the engine exhaust stream.
Combustion of fuel with pure oxygen also results in higher flame temperatures that are intolerable by existing engines. To overcome this problem, a portion of the exhaust gas may be circulated and mixed with an oxygen oxidizer. Since carbon dioxide is the major portion of the exhaust gas, this involves circulating at least a portion of the carbon dioxide as an inert gas to perform a similar temperature reduction during combustion within the engine as the nitrogen gas discussed above in conventional combustion. Thus, carbon dioxide capture and storage (CCS) only needs to recover the remaining carbon dioxide that is not recycled.
However, the natural sources of hydrocarbon fuels typically include some nitrogen that may not be economically separated from natural gas during liquefaction. Since the fuel for oxyfuel combustion is typically a liquefied hydrocarbon (e.g., liquefied natural gas) in which a part is nitrogen, the use of such fuel results in a part of the exhaust gas being nitrogen. Oxygen used as an oxidant in oxyfuel combustion may also contain some impurities inert to combustion, such as nitrogen or argon. Once as much carbon dioxide as possible is removed from the nitrogen, the nitrogen can be vented to the atmosphere as an exhaust gas. However, a significant portion of the exhaust gas remains carbon dioxide, and thus this approach still results in a proportion of the carbon dioxide atmosphere being vented, which is undesirable.
The present invention seeks to improve the capture and storage of carbon dioxide from oxy-fuel combustion exhaust.
Thus, in accordance with one embodiment of the present invention, there is provided a method of recovering carbon dioxide (CO) from an oxy-fuel combustion engine exhaust stream 2 ) The method at least comprises the following steps:
(i) Providing and separating an oxy-fuel combustion engine exhaust stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
(ii) Condensing at least a portion of the first offgas stream to provide a partially condensed offgas stream;
(iii) Separating the condensed waste gas stream to provide a second waste gas stream and a second liquefied CO 2 And (3) flow.
According to a second aspect of the present invention there is provided a method for recovering carbon dioxide (CO from an oxy-fuel combustion engine exhaust stream 2 ) The apparatus comprising:
(a) An exhaust separator for separating an oxy-fuel combustion engine exhaust stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
(b) An exhaust gas condenser for at least partially condensing the first exhaust gas stream and providing a partially condensed exhaust gas stream; and
(c) An exhaust gas separator for separating the partially condensed exhaust gas stream into a second exhaust gas stream and a second liquefied CO 2 And (3) flow.
Drawings
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic illustration of a method of recovering carbon dioxide from an oxy-fuel combustion engine exhaust stream;
FIG. 2 is a schematic illustration of a method of recovering carbon dioxide from an oxy-fuel combustion engine exhaust stream according to one embodiment of the invention;
fig. 3 to 11 are schematic diagrams of variants of the method shown in fig. 2;
FIG. 12 is a more detailed schematic view of a method of recovering carbon dioxide from an oxy-fuel combustion engine exhaust stream based on FIG. 1; and
FIG. 13 is a schematic diagram of the method shown in FIG. 12, including methods and apparatus according to embodiments of the invention.
Detailed Description
The present invention provides a method for recovering carbon dioxide from an oxy-fuel combustion engine exhaust stream.
Oxy-fuel combustion is a process in which pure oxygen (rather than air as the primary oxidant) is used to combust the fuel. The primary effluent emissions are water and carbon dioxide, and water can be easily condensed and removed using ambient cooling, conforming the exhaust gas to efficient carbon capture technologies.
Carbon dioxide capture and storage (CCS) is an increasingly important system for reducing atmospheric carbon dioxide emissions from engines. For modern, traditional power plants, carbon dioxide capture and storage can significantly reduce atmospheric carbon dioxide emissions. The engine exhaust may pass through one or more coolers and separators to remove at least that portion of the exhaust that is water (typically liquid water) and thus concentrate the carbon dioxide.
In oxy-fuel combustion applications, the concentrated carbon dioxide stream may then be partially used for recovery into the engine as an inert gas to improve engine combustion control, including providing a cool down function (as with nitrogen when air is used in a standard combustion engine). Typically, this is the main cyclic process that occurs.
Meanwhile, it is expected that as much carbon as possible will be recovered from the portion of the exhaust gas that is not used for recycling back to the engine (hereinafter referred to as the 'recovery stream') because the recovery stream is still rich in carbon. The recycle stream may be treated by various separation, compression, cooling and dehydration steps in order to try and maximize the liquefaction of carbon dioxide to form liquefied CO 2 (LCO 2) (as a kind of'Useful product') to capture carbon, liquefying CO 2 Can be conveniently used or stored without any atmospheric release or venting.
In one particular arrangement, the recovery stream is passed through a 'regulator train' (containing a water splitting step (to further reduce the water content)) and then passed through a supercharging device such as a compressor or fan. Compression is typically followed by cooling (e.g., an aftercooler) and then a dedicated dehydration process is possible to further reduce the moisture content of the compressed gas. This may be followed by a condenser and separator to provide the final highly enriched liquefied CO 2 Stream of liquefied CO 2 The stream includes at least a majority of the carbon dioxide in the recovered stream.
Liquefying CO 2 May be defined as the 'captured carbon', i.e. the portion of the non-recycled exhaust gas that has been 'effectively recovered'. However, a portion of the recycle stream cannot be liquefied by the recycle process. This is because the use of hydrocarbon fuels, particularly methane or methane-rich fuels, typically results in such fuels containing a proportion of nitrogen. During the processing of the natural gas source for use as a fuel, it is often economically unfeasible to remove all of the nitrogen from the natural gas source. Typically, the treatment involves liquefying the fuel to make it easier to transport from the source to the point of use.
Similarly, the oxidant (e.g., liquefied oxygen) produced by the air separation unit may also result in a portion of the oxidant being non-condensable inert gases (e.g., nitrogen and argon) that are non-condensable at temperatures and pressures suitable for the liquefaction of carbon dioxide.
Since nitrogen (and any argon, etc.) is inert during combustion, the presence of nitrogen (and any argon, etc.) in the fuel and/or oxidant will cause it to continue to exist in the exhaust. All conventional non-cryocoolers, knock-out drum(s), separators, etc. do not affect the phase or presence of inert non-condensable gases in the exhaust stream such that the final cooling and separation of the carbon dioxide rich recycle stream (to provide the liquefied carbon dioxide stream discussed above) results in an exhaust gas comprising the portion of inert non-condensable gases in the original hydrocarbon fuel or oxygen source stream.
As discussed above, some or all of the exhaust gas so formed may be recycled to combustion, but this may result in the accumulation of non-condensable inert gases (nitrogen, argon, etc.) in the combustion exhaust stream, which results in a decrease in the efficiency of the exhaust conditioning process over time and ultimately in failure of the oxy-fuel combustion system.
Thus, one possibility is to release the exhaust gas thus formed into the atmosphere as exhaust gas. If the exhaust gas is 100% non-condensable inert gas (i.e. completely free of carbon dioxide), this does not result in any greenhouse gas emissions. However, while cooling and liquefying carbon dioxide by conditioning processes known in the art is most effective in carbon capture, near 100% carbon capture efficiency has not been achieved in the presence of non-condensable inert gases. Thus, there is always a proportion of carbon dioxide that becomes part of the exhaust gas from the final liquid carbon dioxide separator. If these exhaust gases are vented to the atmosphere, this will result in the release of that portion of the carbon dioxide in the exhaust gases to the atmosphere, which will be an undesirable greenhouse gas emission.
In one embodiment of the present invention, a method for recovering carbon dioxide (CO) from an oxy-fuel combustion engine exhaust stream is provided 2 ) The method at least comprises the following steps:
(i) Providing and separating an oxy-fuel combustion engine exhaust stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
(ii) Condensing at least a portion of the first offgas stream to provide a partially condensed offgas stream; and
(iii) Separating the condensed waste gas stream to provide a second waste gas stream and a second liquefied CO 2 And (3) flow.
The oxyfuel combustion engine exhaust stream of step (i) typically has undergone an initial conditioning train or one or more processes to remove a portion of the water in the exhaust stream and/or to provide a recycle stream with a portion of the carbon dioxide back into combustion to aid in combustion control.
The oxy-fuel combustion engine exhaust stream to be treated in accordance with the present invention is also typically subjected to further conditioning to recover as much of the useful product as possible, conditioning typically including further water removal, compression, cooling, condensation and separation to provide a useful bottom liquefied carbon dioxide stream and a top 'waste' stream, which is hereinafter defined as the "first exhaust stream".
In one embodiment, the method of the present invention optionally comprises: wherein the oxy-fuel combustion engine exhaust stream is a portion of the initial oxy-fuel combustion engine exhaust stream that is cooled, separated, compressed, and dehydrated. Alternatively, such an initial oxy-fuel combustion engine exhaust stream is divided into a portion known as a recycle stream and a portion known as a recycle stream.
The present invention is not limited by the nature of or provision of cooling required for one or more condensation processes applied to an oxy-fuel combustion engine exhaust stream capable of providing a first exhaust stream.
The first exhaust stream typically includes a proportion of nitrogen and a proportion of gaseous carbon dioxide.
In steps (ii) and (iii) of the process of the invention, the first offgas stream is condensed to provide a partially condensed offgas stream, and the condensed offgas stream is subsequently separated to provide a second offgas stream and a second liquefied CO 2 And (3) flow. Optionally, condensing at least a portion of the first exhaust stream in step (ii) of the method of the invention is provided by using one or more of a combustion engine fuel source stream and/or an oxidant source stream. Such a stream typically has available cooling power if provided at a temperature below ambient temperature, preferably below-50 ℃.
At least a portion of the first exhaust stream has a condensation temperature that is lower than the condensation temperature of the first exhaust stream.
Optionally, condensing at least a portion of the first exhaust stream is performed by direct cooling, or indirect cooling, or both direct and indirect cooling, of the (against) combustion engine fuel source stream and/or oxidant source stream.
Direct cooling of the first exhaust stream may be provided by direct heat exchange with the combustion engine fuel source stream via one or more suitable heat exchangers in a manner known in the art.
The indirect cooling of the first exhaust stream may be provided by one or more intermediate cooling mediums, systems, or processes in heat exchange with the combustion engine fuel source stream and/or the oxidant source stream. Such intermediate cooling media, systems, and processes are known in the art and include providing an intermediate cooling or refrigerant medium that is capable of passing between heat exchangers in the path of the combustion engine fuel source stream and/or the oxidant source stream and through one or more heat exchangers in the path of the first exhaust gas stream portion.
Thus, optionally, at least a portion of the first exhaust stream is cooled by a cooling medium cooled by one or more of the combustion engine fuel source stream and/or the oxidant source stream.
Those skilled in the art will appreciate that the combustion engine fuel source stream and/or the oxidant source stream may generally provide cooling power based on their source temperatures and/or pressures, and that such cooling power may be used directly, indirectly, or both directly and indirectly in a number of methods or processes prior to use in the combustion engine to help condense at least a portion of the first exhaust stream.
Those skilled in the art will also appreciate that arrangements using cooling power from the fuel source stream and/or source stream of the combustion engine may be maximized depending on various factors including the size of the engine, the desired flow of the fuel source stream, and the desired amount of the first exhaust stream to be condensed.
Typically, at least one of the combustion engine fuel source stream and/or the oxidant source stream is a low temperature fuel source stream and/or a low temperature oxidant source stream. Various low temperature hydrocarbon fuel sources are known in the art, and are typically based on one or more liquefied hydrocarbon gases.
In one embodiment, the fuel is a gas suitable for an internal combustion engine, such as methane, or a mixture of two or more gases rich in methane (typically hydrocarbon gases). The method is thus particularly, but not exclusively, applicable to engines for heavy machinery and engines for ships, as well as for industrial power generation with combustible gas elements in the fuel gas, for example.
A typical hydrocarbon cryogenic fuel source stream is liquefied natural gas (liquefied natural gas, LNG). Other suitable fuel sources are natural gas liquids (natural gas liquid, NGL) or liquefied petroleum gases (liquid petroleum gas, LPG) such as propane or butane. The present invention is not limited by the nature of the hydrocarbon fuel source.
For the combustion of oxy-fuel, an oxygen source is required. The provision of liquefied oxygen as an oxidizing agent is well known in the art and will not be discussed further herein. Liquefied oxygen also has available cooling power.
Alternatively, the method of the present invention is capable of recovering carbon dioxide from a power plant (power generator) that includes a gas turbine.
Alternatively, the method of the present invention can provide a second waste gas stream comprising <50% carbon dioxide in the first waste gas stream, optionally comprising <75% carbon dioxide of the first waste gas stream.
In this way, the present invention significantly increases the efficiency of carbon capture from the exhaust gas, particularly from the portion of the exhaust gas (referred to herein as the recovery stream) that is not used for recirculation back into the engine. In recovering the flow through the first separation to provide a first liquefied CO 2 After the stream and the first offgas stream, it is now possible to provide from the recovery stream by the process according to the invention>Carbon capture efficiency of 90%. In practice, the invention enables the recovery from a recycle stream>95% or even>97% carbon capture efficiency.
Alternatively, the method of the present invention can provide for the liquefaction of the second CO 2 The stream is transferred to a storage. The second LCO2 stream may be combined with the first LCO2 stream.
Alternatively, the method of the present invention can provide for the partial or complete second liquefaction of CO 2 The flow is recycled back to the oxy-fuel combustion engine.
Alternatively, the method of the present invention can provide for the partial or complete second liquefaction of CO 2 The stream is recycled to the recovery stream.
In one embodiment of the present invention, a method for recovering carbon dioxide (CO) from an oxy-fuel combustion engine exhaust stream is provided 2 ) The method at least comprises the following steps:
-dividing the oxy-fuel combustion engine exhaust stream into a recycle stream and a recovery stream;
-treating the recycle stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
-condensing at least a portion of the first offgas stream to provide a partially condensed offgas stream; and
separating the partially condensed offgas stream to provide a second offgas stream and a second liquefied CO 2 And (3) flow.
The present invention also provides a method for recovering carbon dioxide (CO) from an oxy-fuel combustion engine exhaust stream 2 ) The apparatus comprising:
(a) An exhaust separator for separating an oxy-fuel combustion engine exhaust stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
(b) An exhaust gas condenser for at least partially condensing the first exhaust gas stream and providing a partially condensed exhaust gas stream; and
(c) An exhaust gas separator for separating the partially condensed exhaust gas stream into a second exhaust gas stream and a second liquefied CO 2 And (3) flow.
Optionally, cooling for the exhaust gas condenser is provided by one or more combustion engine fuel and/or oxidant source streams.
Optionally, the cooling for the exhaust gas condenser is performed by direct cooling, or indirect cooling, or both direct and indirect cooling for the combustion engine fuel source stream and/or the oxidant source stream.
Optionally, the engine fuel source and/or the oxidant source is a cryogenic fuel source.
Optionally, one cryogenic fuel source stream is Liquefied Natural Gas (LNG).
Optionally, one source of cryogenic oxidant is liquefied oxygen.
Optionally, a portion of the first exhaust stream is cooled by a cooling circuit having a cooling medium cooled by one or more combustion engine fuel and/or oxidant source streams.
Alternatively, the oxy-fuel combustion engine exhaust stream is provided from an initial oxy-fuel combustion engine exhaust stream that is cooled, separated, compressed, and dehydrated.
Optionally, the second waste gas stream comprises <50% carbon dioxide in the first waste gas stream, optionally <75% carbon dioxide of the first waste gas stream.
Alternatively, the apparatus is capable of providing a carbon capture efficiency of >90% from the recycle stream, alternatively >95% or >97% from the recycle stream.
Optionally, the apparatus further comprises a device for second liquefying CO 2 A reservoir of the stream.
Optionally, the apparatus further comprises a recycle loop for the second liquefied CO 2 A portion of the flow enters the oxy-fuel combustion engine.
Optionally, the apparatus comprises:
-a splitter (splitter) for splitting an oxy-fuel combustion engine exhaust stream into a recycle stream and a recovery stream;
-one or more coolers, compressors and separators for separating the recycle stream into a first liquefied CO 2 A stream and a first exhaust stream;
-an off-gas condenser for at least partially condensing the first off-gas stream and providing a partially condensed off-gas stream; and
an exhaust gas separator separating the partially condensed exhaust gas into a second exhaust gas stream and a second liquefied CO 2 And (3) flow.
Referring to the drawings, FIG. 1 shows a schematic diagram of an oxy-fuel combustion engine exhaust stream that is subjected to certain treatments to enable provision of the oxy-fuel combustion engine exhaust stream that is useful in the present invention.
Fig. 1 shows that fuel 2, e.g., liquefied Natural Gas (LNG), passes through a fuel heater 4 and a source of oxygen 6 passes through an oxygen heater 8, after which both the fuel 2 and the oxygen 6 enter an internal combustion engine (internal combustion engine, ICE) 10. The fuel and oxygen are combusted in the ICE 10 and exhaust gas 12 is provided in a manner known in the art. The exhaust gas passes through an exhaust gas cooler 14 and to a water knockout vessel (water knockout) 16, which is capable of separating a portion of the water in the exhaust gas 12 into a bottom water stream 17 and a top gaseous stream 18 toward a recirculation fan 20. The recirculation fan 20 provides momentum to the gaseous stream 18 around the recirculation loop 22 such that at least a portion of the gaseous stream 18 formed at least in part from carbon dioxide is circulated back into the ICE 10 as a recirculation stream to perform the temperature reduction function as an inert gas in the manner described above.
By individually controlling the amounts or proportions of oxygen, water, and carbon dioxide, the combination of oxygen 6 and recovered carbon dioxide in the recirculation loop 22, as well as any moisture still present within the recirculation loop 22 or any additional water added, allows the combustion process in the ICE 10 to be tailored to specific requirements or needs.
Fig. 1 also shows a splitter 24 (e.g., a tee) for splitting the gaseous carbon dioxide stream 18 into a recycle stream (typically primary) to enter the recirculation loop 22 and a recycle stream (typically secondary) to enter the liquefied carbon dioxide (LCO 2) conditioning train, depending on the cycle demand and other engine conditions.
Examples of the first reclamation adjustment queue shown in fig. 1 include: a further water knock out tank 26 for further reducing the proportion of any water in the gaseous stream of carbon dioxide before the gaseous stream of carbon dioxide enters a compressor 28; an aftercooler 30 for reducing the temperature of the compressed stream; a dedicated dewatering device 32; and a condenser 34 followed by a separator 36. Separator 36 provides LCO2 stream 38, and provides an exhaust stream, in a manner known in the art.
The cooler 30 and the dehydration engine 32 may optionally be provided with drain pipes in a manner known in the art and controlled in a manner known in the art, primarily to prevent ice or gas hydrates from forming in the condenser 34.
By liquefying as much as possible the remainder of the CO in the recycle stream 2 At least partially reduce CO from the combustion engine to the atmosphere 2 And (5) discharging. However, one component of the first exhaust stream is nitrogen. Gaseous nitrogen is typically part of the light hydrocarbon fuel as a component of the original hydrocarbon gas extracted from the hydrocarbon gas source. It is not economically viable to remove all of the nitrogen during the liquefaction of the gaseous fuel to form a liquefied gaseous fuel that is easier to transport between the hydrocarbon gas source and its use.
As described above, a portion 40 of the first exhaust stream may be vented to the atmosphere to mitigate nitrogen accumulation in the process of fig. 1. The nitrogen accumulation will be the result of reusing at least some of the first exhaust gas stream in exhaust gas recirculation loop 42 to return it to gaseous stream 18, after which a proportion of the gaseous stream is used in recirculation loop 22. Since nitrogen is not liquefied by any condensing or separating process used to condense and separate carbon dioxide, nitrogen will accumulate in the recycle loop, which will reduce the efficiency of the remaining process.
However, releasing the first exhaust stream 40 into the atmosphere also releases carbon dioxide in the overhead stream that is not liquefied and separated by the condenser 34 and separator 36. Releasing such gases to the atmosphere is still undesirable and is not considered to be the most efficient carbon capture.
FIG. 2 illustrates an embodiment of the invention wherein at least a portion 40 of the first exhaust stream 46 is diverted from the splitter 44 to a second recovery process for at least partial condensation in an exhaust condenser 48 before entering an exhaust separator 50 to enable provision of a second exhaust stream 52 and a second liquefied CO 2 Stream 54.
The second exhaust stream 52 comprises <50% of the carbon dioxide in the first exhaust stream 40, optionally comprises <60%, or <65%, or <70%, or <75%, or <80%, or lower of the carbon dioxide in the first exhaust stream 40.
In this way, the present invention significantly improves the efficiency of carbon capture from the engine exhaust. The present invention can provide >90% overall carbon capture efficiency from the initial recovery stream produced by the splitter 24. In practice, the present invention enables carbon capture efficiencies of >92%, or >95%, or >96%, or >97%, or >98%, or >99% from the recovery stream. According to calculations, using an LNG fuel stream with 1.5mol% nitrogen, the present invention can achieve 97% carbon capture efficiency. Depending on the 'quality' of the LNG fuel, this ratio may be higher. Thus, the present invention may achieve near or up to 100% carbon capture.
Fig. 3 shows a first variant of the embodiment of the invention shown in fig. 2, in which the second LCO2 stream 54 passes through an LCO2 heater 56, which is able to prevent the formation of dry ice (solid carbon dioxide), which may be caused by its expansion before the carbon dioxide is recycled.
Fig. 4 shows another variant of the embodiment of the method of the invention shown in fig. 2, wherein the second LCO2 stream is sent to a reservoir, optionally to the same location or reservoir as the LCO2 38 provided from the bottom of the LCO2 separator 36.
Fig. 5 shows a variation of the embodiment of the method of the present invention shown in fig. 4, wherein a pump 60 is capable of returning additional recovered carbon dioxide to directly add the liquefied carbon dioxide stream 38 from the LCO2 separator 36.
Fig. 6 is a variation of the embodiment of the method of the present invention shown in fig. 3, wherein the cooling power required in the exhaust gas condenser 48 is provided directly by having the combustion engine fuel source stream (which is fuel 2) after it passes through the initial fuel heater 4 and before it passes through the further fuel heater 4a and into the ICE 10. Thus, the fuel 2 is used for direct cooling against a portion of the first exhaust flow 40.
Fig. 7 is a variation of the embodiment of the method of the present invention shown in fig. 3, wherein cooling in the exhaust gas condenser 48 is provided by passing a combustion engine oxidant source stream (which is oxygen 6) through the first oxygen heater 8, then directly through the exhaust gas condenser 48, then through the secondary oxygen heater 8a, and then into the internal combustion engine 10.
Fig. 8 is a variant of the embodiment of the method of the invention shown in fig. 6, which now comprises a heat exchange circuit 62, which heat exchange circuit 62 comprises a heat exchange medium (working fluid) which is capable of transferring cooling power between the primary fuel heater 4 and the exhaust gas condenser 48. In this way, cooling in the exhaust gas condenser 48 is provided indirectly from the fuel 2 via the first fuel heater 4.
Fig. 9 is a variation of the embodiment of the method of the invention shown in fig. 7, wherein a heat exchange circuit 62a is provided between the off-gas condenser 48 and the initial oxygen heater 8 such that cooling for the off-gas condenser is provided indirectly from the liquefied oxygen 6 as the source of oxidant.
Fig. 10 is a variation of the embodiment of the method of the present invention shown in fig. 8 and 9, wherein a third heat exchange circuit 64 is shown providing cooling of the exhaust gas condenser 48 by separating the heat exchange medium (working fluid) in the third cooling circuit 64 between the primary fuel heater 4 and the primary oxygen heater 8, thereby providing some cooling power from both the fuel source stream and the oxidant source stream.
Fig. 11 shows another variant of the embodiment of the method of the invention shown in fig. 2, in which a second LCO2 stream 54 is sent for engine cycling via recirculation loop 22.
Fig. 12 shows the background of another example of the invention.
In fig. 12, a combustion fuel source stream of LNG (stream 301) first passes through an LNG vaporizer 400 where the stream cools a Cold Exchange Working Fluid (CEWF) in a cold exchange working fluid (cold exchange working fluid, CEWF) circuit 410, described in more detail below. The CEWF circuit is used for preventing CO 2 CO in condenser 464 2 Is frozen (discussed in more detail below). In CEWF circuit 410, CEWF is controlled at-50 ℃. In LNG vaporizer 400, LNG is fully vaporized and superheated to-60 ℃ (stream 302).
This temperature is still too low for use in a gas engine and therefore requires further heating in a fuel gas heater 412 which heats the fuel gas to +10 ℃ to form the fuel gas stream 303. The heat source for this heating is a hot exhaust gas (stream 101) whose temperature is sufficiently high that no intermediate working fluid is required.
The fuel gas stream 303 is sent to a gas engine (not shown) where the Gas Valve Unit (GVU) of the engine controls the flow of gas.
Similarly, an oxygen fuel source is provided as a LOX (liquid oxygen) stream 401 that must be vaporized prior to being fed to the combustion engine. The stream first passes through LOX evaporator 406 to provide CO via CEWF loop 410 2 The cooling required for the condenser 464 is balanced. Hotter O 2 Stream 402 exits LOX evaporator 406 as a vapor-liquid mixture at-157 ℃. For better control, this stream is then superheated by oxygen heater 414 to-140 ℃ (stream 403). Regulating O by using control valve 407 2 To maintain a small target excess O in the engine exhaust stream 101 2 The control valve 407 expands the stream 403 to an exhaust cycle pressure of 0.3 bar (gauge) (bar (g)) in stream 404.
After combustion (not shown), the combustion exhaust stream 101 from the gas engine is at a temperature of +170 ℃ and is sent to the fuel gas heater 412 and the oxygen heater 414 for cooling and to provide a heat source for heat exchange in 412 and 414 as discussed above. Due to exhaust gas to fuel gas and O 2 Heat is provided and the temperature of the exhaust gas is gradually reduced such that the oxygen heater 414 is at a temperature of +145℃ (stream 104).
Since a portion of the exhaust stream 101 must be recycled back to the engine, a recirculation fan 416 is required to overcome the system pressure drop. As with any compression, fans operate more efficiently when the suction temperature is lower. Thus, the now cooler exhaust gas (stream 104) is further cooled to +45℃ (stream 105) in another exhaust gas cooler 418 using cooling water. This cooling process condenses a significant portion of the water in the exhaust 104 that must be removed from the gas in the fan scrubber 420 (stream 114) before it enters the recirculation fan 416 (stream 106). The recirculation fan 416 increases the exhaust pressure to 0.4 bar (gauge pressure) with an accompanying temperature rise to around +62℃, with the exhaust being the exhaust gas stream 107.
Since a lower temperature is preferred for both subsequent compression of the recovered portion of the exhaust gas and engine intake, the exhaust gas stream 107 from the recirculation fan 416 passes through a water cooled recycle cooler 422 which returns the exhaust gas temperature to +45 ℃ as cooling stream 109, which again results in some condensation of water.
A portion of the cooling stream 109 is diverted as a recycle stream 201 (discussed further below) to the carbon capture portion of the process, while the remainder is recycled back to the engine as a first recycle stream 110. Small, relatively rich O from a carbon capture section (discussed further below) 2 May also be returned to the loop to produce a combined recycle stream 111, the combined recycle stream 111 being slightly cooler than stream 110 and containing slightly more O 2 。
Then, the previously discussed O fed into stream 404 2 A combined recycle stream 111 is introduced to produce a desired engine intake component stream 112. Adding cold O in stream 404 2 Causing the exhaust temperature to drop to +28 c and more water to condense out of stream 112. This water is removed as stream 115 from a Recycle separator 424, while liquid-free gas is sent as stream 113 to the engine intake.
At the same time, the recycle stream 201 is first passed through a Suction Scrubber (section Scrubber) 450 to remove water as stream 226 so that no liquid enters the CO as stream 202 2 A compressor 452.
In CO 2 In compressor 452, the gas will undergo at least two, and possibly three (not shown) compression stages. After each compression stage, both the pressure and the temperature of the gas rise. Thus, after each compression stage, the gas is cooled to +45℃ (first in the intercooler 454 after the first compression stage and then in the aftercooler 456 after the final compression stage), and after each cooling (stream 227 and stream 228), water is separated by the inter-stage separator tank (interstage knockout drum) 458 and the final discharge separator tank (final discharge knockout drum) 460. The compressed gas is finally used as +45℃andA compressed stream 209 at 17 bar (gauge), but also as water saturated gas, leaves the compression process.
To prevent subsequent CO 2 Any ice or gas hydrates are formed during condensation and the compressed gas stream 109 passes through the desiccant bed 462 to adsorb moisture in the stream, thereby producing a dry stream 210.
Drying stream 210/211 through CO 2 A condenser 464 for condensing the CO 2 Cold CEWF in CEWF circuit 410 at the condenser compresses the dry CO 2 The stream is cooled to-31℃resulting in a major part of the CO 2 Condensing. Due to the presence of non-condensable substances (e.g. nitrogen or excess O) in the exhaust gas 2 ) The post-condenser stream 212 is not fully condensed under these conditions. Post condenser stream 212 is liquefying CO 2 Separated in separator 466 to provide first LCO2 stream 213 and first exhaust stream 215. From liquefied CO 2 LCO2 product stream 213 of separator 466 may be sent as stream 225 to LCO2 reservoir for subsequent shipment or use.
A portion of the first exhaust gas stream 215 may be expected to be returned to the exhaust cycle as recycle stream 216. This has the effect of bringing about O 2 The additional benefit of supply minimization is that there is wasted O 2 Fewer.
However, the first offgas stream 215 now has the highest percentage of non-condensable gases, particularly nitrogen content of the LNG fuel stream 301. Recycling all of the non-condensable gases will cause non-condensable gases to accumulate over time, resulting in efficiency losses and even eventually failure of the oxy-fuel combustion system.
The first exhaust stream 215 also still contains about 81 mole percent carbon dioxide, and thus venting the remainder of the first exhaust stream 218/219 as exhaust also vents carbon dioxide that is still in the first exhaust stream 215.
Fig. 13 shows the application of an embodiment of the method and apparatus of the present invention to the diagram shown in fig. 12.
Fig. 13 shows that stream 218 is diverted into exhaust condenser 522 at junction 520 of the relevant portion of stream 218 of first exhaust stream 215 (rather than discharging stream 218) for condensing that portion 218 of first exhaust stream 215 to provide partially condensed exhaust stream 219. The partially condensed exhaust stream 219 then enters an exhaust separator 526 and is separated to provide a second exhaust stream 220 having a substantially reduced carbon dioxide fraction, and a second liquefied carbon dioxide stream 222.
The second LCO2 stream 222 may pass through CO 2 Heater 532 is recycled to prevent dry ice from forming in stream 224 after expansion through valve 540, before combining with stream 204, before re-entering inter-stage separation tank 458.
The skilled artisan will recognize that the second LCO2 stream 222 may be stored elsewhere in the circuit shown in fig. 13, or with the first LCO2 stream 213.
Fig. 13 shows an off-gas condenser 522 provided by cooling power from the cold exchange loop 410 provided by streams 542 and 544 provided from the first LNG vaporizer 400 and the first LOX vaporizer 406. Cooling in LNG vaporizer 400 and LOX vaporizer 406 is provided from initial LNG fuel stream 301 and initial LOX fuel stream 401, as described above. The cold exchange loop 410 may be provided to an exhaust condenser 522 and CO 2 Condenser 464 is then recycled toward first LNG vaporizer 400 and first LOX vaporizer 406 in exchange loop 410.
The skilled artisan will appreciate that cooling of off-gas condenser 522 may be provided directly by first LNG vaporizer 400 and/or first LOX vaporizer 406, or indeed by another cooling source.
The method shown in fig. 13 may be calculated to achieve an optimal cooling power arrangement based on the desired amount of fuel source, amount of liquefied carbon dioxide, efficiency of the engine, etc. to provide at least the exhaust condenser 522 with the best possible cooling power to cause CO in the first exhaust stream portion 218 sent thereto 2 Condensation is maximized.
By way of example only, captured 'useful product' liquefied CO 2 Details and parameters of stream 213, portion 218 of first exhaust stream 215, and second exhaust stream 220 are as follows:
the present invention provides a method and apparatus that is particularly capable of further utilizing cooling power available from the use of one or more combustion engine fuel sources and/or oxidant sources, particularly using a cryogenic fuel source such as liquefied natural gas and/or a cryogenic oxidant source such as liquefied oxygen.
The present invention is not limited to the nature of the combustion engine fuel source nor to the sequence or location of suitable heat exchangers capable of performing the steps of the method of recovering carbon dioxide from any oxy-fuel combustion engine exhaust stream to provide a second exhaust stream in which the amount of carbon dioxide is reduced, preferably completely or substantially minimized. Thus, the second exhaust stream may be released into the atmosphere with minimal release of carbon dioxide in the oxy-fuel combustion engine exhaust stream.

Claims (27)

1. Recovery of carbon dioxide (CO) from oxy-fuel combustion engine exhaust streams 2 ) The method at least comprises the following steps:
(i) Providing and separating an oxy-fuel combustion engine exhaust stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
(ii) Condensing at least a portion of the first offgas stream to provide a partially condensed offgas stream; and
(iii) Separating the condensed waste gas stream to provide a second waste gas stream and a second liquefied CO 2 And (3) flow.
2. The method of claim 1, the method further comprising:
(ii) At least a portion of the first exhaust stream is condensed using one or more combustion engine fuel source streams and/or an oxidant source stream.
3. The method of claim 2, the method further comprising:
(ii) At least a portion of the first exhaust stream is condensed by direct cooling, or indirect cooling, or both direct and indirect cooling, against a combustion engine fuel source stream and/or an oxidant source stream.
4. A method according to claim 2 or 3, wherein the engine fuel or oxidant source is a low temperature fuel or oxidant source.
5. The method of claim 4, wherein one cryogenic fuel source stream is Liquefied Natural Gas (LNG).
6. The method of claim 4, wherein one low temperature oxidant source stream is liquefied oxygen.
7. The method of any of claims 4 to 6, wherein at least a portion of the first exhaust stream is cooled by a heat exchange medium (working fluid) cooled by one or more combustion engine fuel and/or oxidant source streams.
8. A method according to any one of the preceding claims for recovering carbon dioxide from a power plant.
9. The method of any of the preceding claims, wherein the oxy-fuel combustion engine exhaust stream is provided by an initial oxy-fuel combustion engine exhaust stream that is cooled, separated, compressed, and dehydrated.
10. The method of any of the preceding claims, wherein the second exhaust stream comprises <50% carbon dioxide in the first exhaust stream, optionally <75% carbon dioxide of the first exhaust stream.
11. The method of any one of the preceding claims, which is capable of providing >90% carbon capture efficiency from a recycle stream of an oxyfuel combustion engine exhaust stream, optionally >95% or >97% carbon capture from the recycle stream carbon capture.
12. The method of any of the preceding claims, further comprising causing the second liquefied CO to 2 The flow passes to the reservoir.
13. The method of any one of claims 1 to 12, further comprising passing a portion or all of the second liquefied CO 2 The flow is circulated into the oxy-fuel combustion engine.
14. The method of any one of claims 1 to 13, further comprising passing a portion or all of the second liquefied CO 2 The stream is recycled to a recycle stream of the oxy-fuel combustion engine exhaust stream.
15. Method according to any one of claims 1 to 14, comprising at least the steps of:
-dividing the oxy-fuel combustion engine exhaust stream into a recycle stream and a recovery stream;
-treating the recycle stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
-condensing at least a portion of the first offgas stream to provide a partially condensed offgas stream; and
-separating the partially condensed exhaust stream to provide a second exhaust stream and a second liquefied CO 2 And (3) flow.
16. A method for recovering carbon dioxide (CO) from an oxyfuel combustion engine exhaust stream 2 ) The apparatus comprising:
(a) An exhaust separator for separating an oxy-fuel combustion engine exhaust stream to provide a first liquefied CO 2 A stream and a first exhaust stream;
(b) An exhaust gas condenser for at least partially condensing the first exhaust gas stream and providing a partially condensed exhaust gas stream; and
(c) Waste ofA gas separator for separating the partially condensed exhaust gas stream into a second exhaust gas stream and a second liquefied CO 2 And (3) flow.
17. The apparatus of claim 16, wherein cooling for the exhaust condenser is provided by one or more combustion engine fuel and/or oxidant source streams.
18. The apparatus of claim 17, wherein cooling for the exhaust gas condenser is by direct cooling, or indirect cooling, or both direct and indirect cooling for a combustion engine fuel source stream and/or an oxidant source stream.
19. The apparatus of claim 17 or 18, wherein the engine fuel source stream is a cryogenic fuel source stream.
20. The apparatus of claim 19, wherein one cryogenic fuel source stream is Liquefied Natural Gas (LNG).
21. The apparatus of claim 19, wherein one source of cryogenic oxidant is liquefied oxygen.
22. The apparatus of any of claims 19 to 21, wherein at least a portion of the first exhaust stream is cooled by a cooling circuit comprising a cooling medium cooled by one or more combustion engine fuel and/or oxidant source streams.
23. An apparatus according to any one of claims 16 to 22 for recovering carbon dioxide from an internal combustion engine.
24. The apparatus of any one of claims 16 to 23, wherein the oxy-fuel combustion engine exhaust stream is provided by an initial oxy-fuel combustion engine exhaust stream that is cooled, separated, compressed and dehydrated.
25. The apparatus of any of claims 16 to 24, wherein the second exhaust stream comprises <50% carbon dioxide in the first exhaust stream, optionally <75% carbon dioxide of the first exhaust stream.
26. The apparatus of any one of claims 16 to 25, being capable of providing >90% carbon capture efficiency, optionally >95% or >97% carbon capture, from a recycle stream of an oxy-fuel combustion engine exhaust stream.
27. The apparatus of any one of claims 16 to 26, further comprising means for the second liquefied CO 2 A reservoir of the stream.
CN202180080203.4A 2020-12-07 2021-12-01 Method and apparatus for recovering carbon dioxide from combustion engine exhaust Pending CN117320796A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB2019205.0A GB2603743A (en) 2020-12-07 2020-12-07 Method and apparatus for recovering carbon dioxide from a combustion engine exhaust
GB2019205.0 2020-12-07
PCT/GB2021/053126 WO2022123215A2 (en) 2020-12-07 2021-12-01 Method and apparatus for recovering carbon dioxide from a combustion engine exhaust

Publications (1)

Publication Number Publication Date
CN117320796A true CN117320796A (en) 2023-12-29

Family

ID=74165925

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202180080203.4A Pending CN117320796A (en) 2020-12-07 2021-12-01 Method and apparatus for recovering carbon dioxide from combustion engine exhaust

Country Status (6)

Country Link
US (1) US20240019208A1 (en)
JP (1) JP2023554590A (en)
KR (1) KR20230117740A (en)
CN (1) CN117320796A (en)
GB (1) GB2603743A (en)
WO (1) WO2022123215A2 (en)

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7850763B2 (en) * 2007-01-23 2010-12-14 Air Products And Chemicals, Inc. Purification of carbon dioxide
US7874140B2 (en) * 2007-06-08 2011-01-25 Foster Wheeler North America Corp. Method of and power plant for generating power by oxyfuel combustion
GB2490301B (en) * 2011-02-25 2018-08-22 Costain Oil Gas & Process Ltd Process and apparatus for purification of carbon dioxide
EP2505948B1 (en) * 2011-03-30 2018-10-10 General Electric Technology GmbH Cryogenic CO2 separation using a refrigeration system
TW201314153A (en) * 2011-07-11 2013-04-01 Alstom Technology Ltd Heat integration for cryogenic CO2 separation
CN111005779A (en) * 2014-09-09 2020-04-14 八河流资产有限责任公司 Production of low pressure liquid carbon dioxide from power generation systems and methods
CN108331625B (en) * 2017-12-29 2019-10-25 华中科技大学 A kind of electricity generation system using the Natural Gas Power Plant smoke evacuation latent heat of vaporization
CN111228978B (en) * 2020-03-17 2024-10-01 赫普能源环境科技股份有限公司 Boiler low-temperature cooling carbon capture system and setting method thereof

Also Published As

Publication number Publication date
GB2603743A (en) 2022-08-17
JP2023554590A (en) 2023-12-28
KR20230117740A (en) 2023-08-09
US20240019208A1 (en) 2024-01-18
WO2022123215A2 (en) 2022-06-16
GB202019205D0 (en) 2021-01-20
WO2022123215A3 (en) 2022-08-04

Similar Documents

Publication Publication Date Title
CN101231131B (en) Purification of carbon dioxide
JP5984192B2 (en) Natural gas liquefaction process
JP6104926B2 (en) Power generation system and corresponding method
US8900355B2 (en) Purification of carbon dioxide
CN107108233B (en) Production of low pressure liquid carbon dioxide from power generation systems and methods
US20100215566A1 (en) Method to condense and recover carbon dioxide from fuel cells
KR20050092770A (en) A refrigeration process and the production of liquefied natural gas
EP2365265B1 (en) Method and installation for separating carbon dioxide from flue gas of combustion plants
US11231224B2 (en) Production of low pressure liquid carbon dioxide from a power production system and method
US20120240616A1 (en) Method and device for treating a carbon dioxide-containing gas stream
JP6357155B2 (en) A method for optimizing condensable component removal from fluids
US20220412649A1 (en) Method for the separation and liquefaction of methane and carbon dioxide with removal of the air impurities present in the methane
CN117320796A (en) Method and apparatus for recovering carbon dioxide from combustion engine exhaust
CN109386735B (en) Combined treatment system and process for zero emission of BOG and carbon dioxide
WO2012114118A1 (en) Process and apparatus for purification of carbon dioxide
GB2229519A (en) Treatment process for gas stream
US9995530B2 (en) Method for the capture of carbon dioxide through cryogenically processing gaseous emissions from fossil-fuel power generation
GB2490301A (en) Carbon dioxide purification
US20220397343A1 (en) Facility for the separation and liquefaction of methane and co2 comprising a vapo/condenser placed in an intermediate stage of the distillation column
US20220397344A1 (en) Combined plant for cryogenic separation and liquefaction of methane and carbon dioxide comprised in a biogas stream
US20220397339A1 (en) Process for separating and liquefying methane and co2 comprising the withdrawal of vapour from an intermediate stage of the distillation column
KR20240075262A (en) Solid carbon dioxide capture apparatus using cryogenic waste energy and method of capturing solid carbon dioxide
KR20240122957A (en) carbon dioxide capture system using cold heat of LNG or LN2 applied with intermediate heat medium with no phase change

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination